Charging control with SMF

Abstract

An SMF receives from an AMF a PDU session create request message requesting establishment of a PDU session for a wireless device. In response to the PDU session create request message, the SMF sends to a CHF a charging policy request message requesting charging policy information for the PDU session. The SMF receives from the CHF a response message comprising the charging policy information for the PDU session. The charging policy information comprises a first charging method. Based on the charging policy information, the SMF determines a charging control rule for the PDU session. The SMF enforces the charging control rule.

What is claimed is: 
     
       1. A method comprising:
 receiving, by a session management function (SMF) from an access and mobility management function (AMF), a packet data unit (PDU) session create request message requesting establishment of a PDU session for a wireless device; 
 sending, by the SMF to a charging function (CHF) and in response to the PDU session create request message, a charging policy request message requesting charging policy information for the PDU session; 
 receiving, by the SMF from the CHF, a response message comprising the charging policy information for the PDU session, wherein the charging policy information comprises:
 a first charging method; and 
 an information element indicating that a first charging rate is applicable for the PDU session; 
 
 determining, by the SMF based on the charging policy information, a charging control rule for the PDU session; and 
 enforcing, by the SMF, the charging control rule. 
 
     
     
       2. The method of  claim 1 , wherein the charging policy request message comprises at least one of:
 an identifier of the wireless device; or 
 an identifier of the PDU session. 
 
     
     
       3. The method of  claim 1 , further comprising sending, by the SMF to the CHF, the charging policy request message via a network function. 
     
     
       4. The method of  claim 1 , further comprising determining, by the CHF, the charging policy information for the PDU session. 
     
     
       5. The method of  claim 4 , wherein the determining is based on at least one of:
 an identifier of the wireless device; 
 a type of PDU session; 
 an access type; 
 a radio access technology (RAT) type; 
 a public land mobile network (PLMN) identifier; 
 an application identifier; 
 a data network name (DNN); 
 a single network slice selection assistance information (S-NSSAI); 
 a session identifier of the PDU session; or 
 user location information. 
 
     
     
       6. The method of  claim 1 , wherein the charging policy information further comprises an address of a first charging function. 
     
     
       7. The method of  claim 1 , further comprising:
 determining, by the SMF and based on the charging control rule, a user plane rule for the PDU session; 
 sending, by the SMF to a user plane function (UPF), a N4 request message requesting to establish or modify a session, the N4 request message comprising the user plane rule for the PDU session and the wireless device; and 
 enforcing, by the UPF, the user plane rule. 
 
     
     
       8. The method of  claim 7 , wherein the N4 request message further comprises an N4 session identifier for the PDU session. 
     
     
       9. The method of  claim 7 , wherein the session is an N4 session. 
     
     
       10. The method of  claim 7 , wherein the user plane rule comprises at least one of:
 packet detection rule; 
 forwarding action rule; 
 QoS enforcement rule; or 
 usage reporting rule. 
 
     
     
       11. The method of  claim 7 , wherein the enforcing the user plane rule by the UPF further comprises:
 sending, by the UPF to the SMF, a resource usage report for the PDU session; and 
 receiving, by the UPF from the SMF, a response message to the resource usage report. 
 
     
     
       12. The method of  claim 1 , further comprising:
 receiving, by a Network Repository Function (NRF) from the SMF, a CHF selection request message comprising PDU session information; 
 determining, by the NRF, an address of a CHF based on the PDU session information; and 
 sending, by the NRF to the SMF, the address of the CHF. 
 
     
     
       13. The method of  claim 12 , wherein the PDU session information comprises at least one of:
 a UE IP address; 
 a type of PDU Session; 
 an access type; 
 a radio access technology (RAT) type; 
 user location information; or 
 information of the SMF for the PDU session. 
 
     
     
       14. A method comprising:
 receiving, by a session management function (SMF) from an access and mobility management function (AMF), a packet data unit (PDU) session create request message requesting establishment of a PDU session for a wireless device; 
 sending, by the SMF to a charging function (CHF) and in response to the PDU session create request message, a charging policy request message requesting charging policy information for the PDU session; 
 receiving, by the SMF from the CHF, a response message comprising the charging policy information for the PDU session, wherein the charging policy information comprises a first charging method; 
 determining, by the SMF based on the charging policy information, a policy and charging control (PCC) rule for the PDU session, wherein the PCC rule comprises at least one of:
 a charging control rule, wherein the charging control rule further comprises at least one of:
 an information element indicating a second charging method; 
 an information element indicating a second charging rate; or 
 an information element indicating an identifier or address of a second CHF; 
 
 a policy control rule comprising a QoS control rule; 
 a policy control rule comprising a gating control rule; 
 a usage monitoring control rule; 
 an application detection and control rule; 
 a traffic steering control rule; or 
 a service data flow detection information; and 
 
 enforcing, by the SMF, the charging control rule. 
 
     
     
       15. The method of  claim 14 , wherein the second charging method further comprises at least one of:
 an information element indicating that an online charging is applicable for the PDU session; 
 an information element indicating that an offline charging is applicable for the PDU session; or 
 an information element indicating that a converged charging is applicable for the PDU session. 
 
     
     
       16. A method comprising:
 receiving, by a session management function (SMF) from an access and mobility management function (AMF), a packet data unit (PDU) session create request message requesting establishment of a PDU session for a wireless device; 
 sending, by the SMF to a charging function (CHF) and in response to the PDU session create request message, a charging policy request message requesting charging policy information for the PDU session; 
 receiving, by the SMF from the CHF, a response message comprising the charging policy information for the PDU session, wherein the charging policy information comprises a first charging method; 
 determining, by the SMF based on the charging policy information, a charging control rule for the PDU session; and 
 enforcing, by the SMF, the charging control rule, wherein the enforcing the charging control rule by the SMF comprises:
 sending, by the SMF to the CHF, a charging data request message requesting to establish a charging session, the charging data request message comprising a requested charging method indication; and 
 receiving, by the SMF from the CHF, a charging data response message comprising an accepted charging method indication. 
 
 
     
     
       17. The method of  claim 16 , wherein the requested charging method indication comprises at least one of:
 an information element indicating an online charging; 
 an information element indicating an offline charging; or 
 an information element indicating a converged charging. 
 
     
     
       18. The method of  claim 16 , wherein the accepted charging method indication comprises at least one of:
 an information element indicating an online charging; 
 an information element indicating an offline charging; or 
 an information element indicating a converged charging.